you should see the movie or read the book. jon krakauer is a very readable but thorough author. i suppose the story is sympathetic to the mccandless, yet there is no avoiding the fact that he was often in over his head. i would call him more of a restless or searching soul than a troubled one. he lived on the edge to feel life more deeply, and never took someone else's version of what was possible as the final word. this left little room for caution as you or I might know it, but opened him to experiences that we can only have vicariously through watching a movie. the characters and cinematography are great too.

another great book by krakauer is "under the banner of heaven" which is about fundamentalist mormons. highly recommended. like you said about into thin air, you don't have to be into mormonism or history really to enjoy. excellent!